An uplink sounding reference signal (SRS) is an uplink signal transmitted by a user equipment (UE) to a base station. The base station measures quality of the uplink channel based on the SRS received.
Currently configuration of SRS transmission may be: for a frequency division duplex (FDD) system and a time division duplex (TDD) system, eight types of transmission periodicities, including 2 ms, 5 ms, 10 ms, 20 ms, 40 ms, 80 ms, 160 ms and 320 ms are supported by UEs. For the TDD system, an SRS may be transmitted in an uplink pilot time slot (UpPTS). When the UpPTS includes only one single carrier-frequency division multiple access (SC-FDMA) symbol, the SC-FDMA symbol can be used for SRS transmission. If the UpPTS includes two SC-FDMA symbols, both SC-FDMA symbols may be configured by the base station for SRS transmission. In the UpPTS, the SRS can be transmitted over the whole uplink bandwidth. Because neither of uplink data and control signaling is transmitted in the UpPTS, SRS transmitted in the UpPTS would not conflict with physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), etc. If the SRS is configured in a regular uplink sub-frame, the SRS is transmitted at the last symbol of the uplink sub-frame. When PUSCH is transmitted in the uplink sub-frame, all UEs should remove the last symbol of the uplink sub-frame.
When an SRS is transmitted in a regular uplink sub-frame, the SRS would conflict with uplink control information. Specifically, in the regular uplink sub-frame, the SRS should not be transmitted in the frequency band of the PUCCH. If a UE needs to transmit an Acknowledgement/Negative Acknowledgement (ACK/NACK) and an SRS simultaneously in the same uplink sub-frame, a shortened format of the ACK/NACK is transmitted or the SRS will not be transmitted. If the UE needs to transmit a Channel Quality Indicator (CQI) and an SRS simultaneously in the same uplink sub-frame, the SRS will not be transmitted. If the UE needs to transmit a scheduling request (SR) and an SRS simultaneously in the same uplink sub-frame, the SRS will not be transmitted.
As can be seen, the prior art does not provide a specific solution for configuring SRS transmission in a system. As a result, SRS can not be transmitted normally.